Sunday, 19 December 2021

KX2 vs KX3 vs IC-705

A BRACE OF BEAUTIES...
...AND THE NEW KID ON THE BLOCK



I've said all along that the Elecraft KX3 is a magnificent radio but I also said that it  feels a little vulnerable for using in the rugged outdoors. Not that it's flimsy or poorly built - it's most definitely not,  but compared to other QRP field radios I own (or have owned in the past), there's always a nervousness about handling it outdoors. I guess a lot of that is due to the unusually high cost of the unit. 

To repeat myself (I do that a lot),  I liken it to driving a Rolls Royce Wraith up to the top of a hill when you know that you should have taken the Land Rover Defender!


 
So maybe the smaller Elecraft KX2 (the smallest fully featured HF radio in the world) is better suited to the job? 

The KX3 is about $400 more expensive and weighs almost twice as much as the KX2, but it benefits from having two extra bands (160M & 6M) as standard. It can also benefit from having an optional Roofing Filter and charger installed (at an extra cost of $260) which aren't available for the KX2. The KX3 can also be fitted with an optional VHF Transverter for $340 and it has FM mode.  Finally, the KX3 has an IQ-Out and panadapter-socket allowing you to connect it to Elecraft's $750 PX3 😵 An internal ATU is available for both radios at a cost of $300.

So the KX3 kit can very quickly get super expensive and I personally consider it to be better suited as something you'd use for low-risk Field Days where you'd have the radio in a Pelican Case in the back of your car and virtually drive right up to a picnic table and set up your station.

The KX2 on the other hand is very much an outdoor radio. It's incredibly small and light and has an amazing battery life (at QRP levels) using the internal Li-ion battery. The screen is identical on both radios but  the idle current drain is fractionally lower on the KX2. It doesn't have any special damage-protection or weatherproofing, but its dimensions just make it easy to handle and reduce the risk of it being dropped I guess.

Having no Top Band (well, no tx) is of no consequence to me, since I almost never use it. Having no 6M band is more of a loss, but again, I don't use it much when out in the field. Like most people, after climbing or hiking to reach a good vantage point, I want to use the most heavily populated bands in order to maximise the number of contacts. Normally, that's 20, 40 & 17M for me.

My KX2 has a slightly better sounding speaker than my KX3 but it's still not good. I know that Elecraft claim most operators will be using headphones and the speaker is more of an emergency backup, but that's a load of tosh to me! If Belka can fit a perfectly good speaker in their tiny receiver, I'm sure Elecraft could have done the same. Jeez, I've got a $20 Chinese UV5R with a superb speaker in it!! If I'm not using headphones, I tend to use a separate speaker with the KX2 and KX3.

The KX2 has a built-in microphone but the vast majority of users plug a hand-mic in. Considering that Elecraft went to so much trouble to build such a tiny transceiver, including an internal battery pack and an internal ATU, I'm staggered that they didn't create a matching microphone! To pair the KX2 with their MH3 is like putting a size 12 Boot on a baby!! Everytime I pick it up I find myself shaking my head. Compared to Yaesu's smaller microphones (or Icoms or Kenwoods), the MH3 is a brick! And it's not even a speaker mic (although the inners indicate that it was possibly meant to have that option)!

 
I know nothing about electronics, but I'm going to see if I can find some help from more advanced operators to find out if the little Yaesu Spkr-Mic can be modified to allow it to be used with the KX radios. If it can, it would be a wonderful upgrade - even if it's only as a mic.

The ATU in the KX2 is definitely not quite as good as the one in the KX3, but to be honest, it's good enough for any antenna that I use. It also seems a tiny bit slower than the KX3 tuner, although that might just be my imagination. 

Like most other QRP operators, I do my best to use resonant antennas because I don't want to waste a single milliwatt, but sometimes you don't have a choice and also, some "resonant" antennas are only resonant at one end of a band and need a bit of tuning at the opposite end.

My SotaBeams 20/40 Linked Dipole and BandHopper EFHW both benefit from a little fine-tuning, so it's good to have the KXAT2 installed. The KXAT2 would really come into its own when users employ a random length wire and I feel quite confident that a usable match would be achieved on virtually any band.


The tiny KX2 fits inside a very small soft case, complete with the (oversize mic) and the very able AX1 antenna which covers 40, 20, 17 and 15M. This is for sure the most compact HF kit around and although that AX1 is a compromise antenna, it has proved itself to be a very capable performer if the conditions are right.

I think perhaps too many people expect too much from this antenna and don't put enough effort into helping it work well. I've even seen people try to use it without the supplied counterpoise wires (there's one for 20M and another for 40M). It can be negatively affected by body capacitance and height, so wherever possible, I use it away from my operating position and often on a raised tripod. That's not always convenient though and sometimes I have to have it connected directly to my radio using Elecraft's little support legs, which add a surprising amount of stability.
 
For power, the KX2 uses a great 2600mAh Lipo battery, which I prefer to the KX3's NiMH arrangement. The good thing about the KX3 battery arrangement is that you can recharge them without removing them from the radio - that's not the case with the KX2. It's a small hardship having to remove the Lipo to use an external charger, but one I wish they'd have overcome at the design stage. If there's one thing I don't like doing with either of these radios, it's opening them up routinely. It's just not a good thing as far as I'm concerned.

Thankfully, I tend not to rely on internal batteries, preferring instead to use a lightweight 13.2V LifePO. I have two of those, one 8.4Ah and one 4.8Ah. I got these from HobbyKing and almost 3 years later, they're still going strong - amazing!
 
The radio itself displays no difference in receive performance to its bigger brother and the only tangible difference (to me at least) is the addition of the dual roofing filter in the KX3. They both receive fabulously, making it easier to pull out those very weak stations from the noise. It's always a pleasure to use Elecraft radios and I never feel like I'm compromised in any way by operating a portable when it's one of these beauties. It's like having a top-end radio in your rucksack.


It's worth pointing out that these two Elecrafts share the same wonderful screen from the K3S Base Station! So opting for the much smaller radio doesn't mean that you're stuck with a much smaller screen - no - they both share one of the best high-contrast LCD screens on the market. No matter how bright and sunny it is outdoors, the screen is always perfectly readable.

The KX3 benefits from being able to provide a 15W output, whereas the KX2 can only manage 12W. Having said that, the KX2 can produce 10W from the internal battery, whereas the KX3 can only manage 5W. To be fair, many buyers of these QRP radios will probably want to use 5W or less anyway!

When out and about, after establishing a contact, my goal is to try and reduce power to the mW range and see how low I can go (that's if the other operator is willing to oblige me). Most operators are good willed enough to play the game and they're often surprised and entertained by it.

So of the two Elecrafts, which one is the best? Well clearly, that would be the KX3 for sure. It's just got more options available for it and is more fully featured. It could easily be used as your main radio in the shack (with a 100W amplifier if you wanted). But you've got to accept that such a fully featured radio would cost an awful lot of money (£2,500 fully loaded) and you'd probably be worried sick every time you took it with you on a hike - but then again maybe not.

The KX2 on the other hand has no Top Band, no 6M, no 4M/2M option and no roofing filter option. But my word, it's TINY!! And it's a stunning performer. Lacking the KX3 options doesn't make the KX2 feel lacking in any way - you still get that mighty 'pride of ownership' feeling, novelty value because of its diminutive dimensions and that stonking SDR receiver with 32-bit DSP and fully adjustable filters. The KX2 can also be used with the Elecraft 100W amplifier for those who want to use the radio as a QRO base station. 


Both radios can be fitted with Elecraft's brilliant Paddles which are very compact but not restrictively so. Sadly, I cannot work CW but it's a great desire of mine to learn it one day. 

At 63yrs old I'm not altogether sure that I am capable of learning what is effectively a whole new language, but then again, retirement is hopefully not too far away. The KXPD2 Paddle can be used with a sidetone on either radio to practise sending morse, so I might give it a go. 

As much as I would LOVE to keep the Elecrafts, I have to admit to the excessiveness of having both models. One of them has to go and after a great deal of deliberation, I've decided it's the KX3. If I didn't already own another HF/VHF/UHF QRP radio, I'd be selling the KX2 instead.  

UPDATE : 29 Dec 2021 : KX3 sold to a friend from the local radio club. Very hard to part with her, but she's going to a good home.

So where does this leave the Icom IC-705?

The IC-705 is so different to the KX2 that I feel I can justify keeping the two radios. The IC-705 not only covers HF but it includes the Top Band, 6M, 2M, 70cm and even provides DSTAR operation. 
The IC-705 is a full SDR radio with a staggering range of features including a full-colour touch screen with a real-time Bandscope & Waterfall - something which can be an amazing help finding a signal on a quiet band or finding a quiet spot in a crowded band.

It also has GPS, Wi-Fi, SoundCard, BlueTooth, QSO Recorder, Remote Operation capability, SD-Card and even a compact Speaker-Mic! Like the KX2 it has a built-in Lipo battery but it can only produce 5W unless you attach an external supply to it, whereupon it will happily go up to 10W. The only thing that people complain about is the lack of a built-in tuner. Personally, I think that's a very unfair complaint considering all those other amazing features which are included. I think buyers should remember that a fully loaded KX3 would cost around £1,000 more than a 705 and it would still be lacking many of it's fine features - you don't even get a microphone with a KX3!!

You can use a variety of ATUs with the Icom and they are all simple to setup and use. Personally, I use an LDG around the house with it and a little Elecraft AT1 when I go outdoors. Needless to say, the LDG is infinitely cheaper than the Elecraft.
 



So yes, I will be keeping my Icom IC-705 alongside the KX2 because they're both amazing in their own rights. The 705 could easily be considered good enough to be the only radio you need in or out of your shack - it's that flexible!

Some readers might wonder why I've not mentioned the YAESU FT-817, FT-818 or XIEGU G90 in this post about QRP radios. Well that's because I've reviewed those elsewhere (click the links). They're great radios and I wish I could have kept hold of them, but I sold them after investing in a 705. 

Finally, I'd like to acknowledge that I am incredibly fortunate to be in a position to afford these radios and appreciate that many Hams can only ever afford a single radio (some can't afford any).  Then again, some people annually spend similar amounts to me on things like Cigarettes, Booze, Football Season Tickets,  and other hobbies.

AND FINALLY, can I just say that everyone has the right to an opinion and most people are quick to give it, but the best opinions come from those who've put their hand inside their wallet, spent their hard-earned money on something and actually spent time with it before spouting off about it. Too many people bad-mouth or recommend equipment that they've never even owned.

Make hay while the sun shines and enjoy whatever you can afford at the time!

73, Tom, M7MCQ.

Feel free to comment below :-) 

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WATERS & STANTON (UK Importer) say this about the KX2...

Elecraft's KX2 “stealth” transceiver can go wherever your imagination takes you. Thanks to state-of-the-art construction techniques, it’s only 5.8 x 2.8 x 1.5” and weighs just 13 ounces—making it the smallest full-featured HF radio on the planet. Yet it puts out up to 10 watts, covers 9 bands, and shares many features with the KX3. It also works with the KXPA100 amplifier. 

To maximize your freedom to roam, you can outfit your KX2 with an internal 2.6 amp-hour Li-ion battery. Current drain is as little as 135 mA, yielding up to 8 hours of typical operation on a single battery charge. There’s also an internal automatic antenna tuner module (KXAT2), which can tune a random wire, dipole, or whip on multiple bands. 

A rear tilt-foot angles the KX2 for use on any surface, from desktop to park bench to rock. The KX2 also makes a great moble rig, and can even be used hand-held. It includes a built-in mic for HT-style operation. 

 The KX2’s powerful 32-bit DSP offers features dual watch, stereo audio, user-programmable filter bandwidths, noise blanking, noise reduction, and auto-notch. RTTY and PSK data modes are built in—no PC needed—as well as a memory keyer and digital voice recorder for transmit. 

Standard Features

  • 80-10 meter ham bands; general coverage receive from 3-32.0MHz (also covers 0.5 to 3 MHz with reduced sensitivity)
  • All modes: SSB, CW, and Data (four sub-modes)
  • Ultra-compact size: 2.8”H x 5.8”W x 1.5”D; 13 oz (less options); low-profile knobs and feet for minimum height
  • Rear tilt foot provides 3-point mount for rugged terrain
  • Custom high-contrast LCD with alphanumeric text display
  • Current drain as low as 135 mA in receive mode
  • High-performance 32-bit floating-point DSP
  • Built-in PSK/TTY decode/encode allows data mode operation without a PC; transmit in data modes using CW keyer paddle
  • Synthesizer has 1-Hz tuning resolution
  • Integrated numeric keypad for direct frequency entry

Receiver

  • Software-defined-radio (SDR) architecture for versatility
  • Switchable preamp and attenuator
  • 8-band RX EQ
  • Simultaneous dual receive over up to +/- 23 kHz for split-DX operation
  • Built-in speaker; stereo jack for headphones or powered speakers
  • Easy-to-use Passband Tuning (PBT) for shift/width/hicut/locut; roofing filters automatically track DSP filter settings
  • Auto-notch removes interfering carriers; adjustable noise reduction and noise blanking; stereo audio effect
  • Center-tuning indicator for CW and data modes; auto-spot

Transmitter

  • Up to 10 W on 80-15 m, 8 W on 12 and 10 m (typ.)
  • 100 W with KXPA100 amplifier
  • Rugged, SWR- and temperature-protected final amplifier stage
  • Use with built-in mic or MH3 (with UP/DN VFO functions)
  • Optional KXPD2 keyer paddle with adjustable contact spacing; easily removable for transport; built-in allen wrench storage
  • CW keyer with 8-50 WPM range; fast, full-break-in keying
  • Built-in digital voice recorder (DVR) with 2 message memories
  • Three CW/DATA message memories
  • Fast, silent, PIN-diode T-R switching – no noisy relays
  • DSP speech processing for excellent “punch”
  • 8-band TX EQ tailors passband to your voice and microphone

Other Features

  • Computer control via supplied USB or RS232 cable
  • Free firmware updates via provided application software
  • Programmable switch (PFn) for access to an often-used menu entry
  • General-purpose and per-band memories store VFOs, modes, etc
  • Full remote-control command set works with popular computer software applications
  • Selectable switch-press tones or full Morse code-based interface
  • Tutorial-style manual ideal for new hams

The Elecraft KX2 is the most powerful compact HF transceiver currently available for ham radio HF operation. Developed from the famous KX3, it is a slimmed down version, but still retains key features that maintain unprecedented performance. And this really is why so many customers use Elecraft for portable operation. 

The KX2 can easily fit into a medium sized coat pocket, yet can deliver up to 12W output. Using the optional internal battery, it easily delivers 5W output for lengthy periods, certainly satisfying most operator’s needs for a typical day out. An additional battery can quickly be replaced or even plugged into the external DC sock for even quicker supply change over.

The bits missing compared to the KX3 may not be of much consequence to a lot of portable operators. You don’t get 160m or 6m operation. You also don’t have the option of using the external PX3 panoramic display. VHF operation on the 4m and 2m bands is also not an option.  There is also no optional roofing filter to improve the bandwidth performance for CW. 

What you cannot ignore is the fun of carrying a complete HF station in your pocket. One of the most attractive options carried over from the KX3. is the auto antenna tuner. This perhaps is one of the great strengths of Elecraft. The auto atu for both the KX3 and KX2 are easily able to handle most antennas including end fed wires. 



5 comments:

VE9KK said...

Good morning Tom, very nice run down of the three radios! I have only of the three owned the KX3 and as I look back I am very sorry I sold it. Never owning a 705 I fully agree with your reasoning to keep the KX2. The 705 has been a big plus for Icom, and I'm glad you enjoy it. The KX3 with the sidebar handles and the protective plastic cover made it (for me anyway) safe for transport, BUT as you made note of, it's a radio you don't want to drop on a rocky hard surface while out and about. To have it get damaged would for sure bring tears to one's eyes.
Again, great review of your 3 radios and enjoy the KX2 and 705.
73,
Mike
VE9KK

MadDogMcQ said...

Thank you Mike for your kind comments. Best wishes to you and your family. Take care and have a lovely Christmas.

73, Tom, M7MCQ.

VE9KK said...

Thank you, Tom and to you and the station manager Merry Christmas and stay safe.
Mike and Julie

Remi said...

Thanks you Tom for the comprehensive review of the 3 popular units. I am in queue to receive the KX2 but have pondered changing to the KX3. Your review has helped with my decision since I already have the IC-705. vy 73 de K1KHU

IrritatedWeasel said...

@Remi - did you keep the IC-705?